Electric meter



(No Model.)

P. O. WAGNER.

ELECTRIC METER.

No. 898,182. Patented Nov. 20, 1888.

N. PETERS. PhMn-Lxihcguphcr. WaihinglamD.C.

UNITED STATES FRANK C. \VAGNER, OF

PATENT Grates.

ANN ARBOR, MICHIGAN.

ELECTRIC METER.

SPECIFICATION forming part of Letters Patent No. 393,132, dated November20, 1888.

A mlication filed August 1'22, 1888.

To all whom it may concern:

Be it known that l, FRANK C. WAGNER, a citizen of the United States,residing at Ann Arbor, county of XVashtenaw, and State of Michigan,temporarily residingiu the City of Mexico and Republic of Mexico, havemadea new and useful invention in Electric Meters, of which thefollowing is aspecification.

My invention relates to that class of devices for measuring electricalcurrents through the agency of heat created by the passage of thecurrent through the instrument which measures and records the currentstrength, and is therefore applicable alike to the measurement of bothdirect and alternating currents of electricity.

To this end it consists in the apparatus hereinafter described, andparticularlypointed out in the claims which follow this specification.It will be fully understood by those skilled in the art to which itrelates by referring to the specification or description which follows,when taken in connection with the accompanying drawings, in which Figurel is a side elevation of my improved meter, showing a part broken awayto better disclose the interior mechanism of the device. Fig. 2 is aplan view thereof, and Fig. 3 is a detail view of the circuit-changingand stepby-step attachments, while Figs. 4, 5, and 6 are detail views ofthe thermal bars and their immediate connections.

D is the base of the instrument, having a standard, S, at one endattached thereto, which in turn supports the thermal controlling-bar A.

M represents the meter or register attachment, similar in its generalconstruction to recording-meters of this general type-such asgas-meters, &c.

B 13 are the binding-posts for attaching the wires which carry thecurrent to be measured.

The thermal bar A is composed of two highly polished bars of steel oranalogous elastic conducting material, H L, and a highlypolished centralstrip of copper, a, insulated from the two steel strips by paper strips6 e, the object of the paper strips being to insulate the strips or barsH L from each other. The interior surfacesjof bars or strips H L arepolished, as is also the copper strip a, to prevent transference of heatas far as possible. This Serial No. 283,499. (No model.)

composite bar is fastened rigidly to the standard S by screw and nut, asshown, and its free end carries a cap, G, of india-rnbber, glass, orother insulating material, held firmly in place by a pin, N, so as toprevent any relative change of position due to the heat action on thebars H and L. The free ends of the bars H and L are connected by aflexible conductor, '10, with binding-posts B, binding-post B beingconnected directly to mercury-cups M and M, respectively.

B is a tilting beam carried by an arm, F, and pivotally connected to theshaft V at T. (See Figs. 1 and 3.) On the ends of this beam are metallicarms Y Y, adapted to dip into mercurycnps M M and M M, according to theposition of the beam.

B" is a bifurcated arm, the bifurcations of which extend over the end ofthe rubber cap or sleeve C. This arm is fixed rigidly to the shaft 'Vand carries two pawls, ,1 f, at its i nner end, adapted to propel theratchetwheel w and pinion p and through them the train of gearcontrolling the recording-meter M.

E is a pivoted arm carrying a weight, 1, at its upper end and having apin, '5, adapted to play in a slot, .2, in arm F, supporting thecircuit-changing beam R.

In Figs. 5 and 0 I have shown a modified form of the compound bar, theparts H and L being made in this instance of polished steel tubesseparated by strips of paper, as before, and having an interveningcopper strip.

The operation of my improved meter is as follows: The current to bemeasured enters by binding-post B and passes out of bindingpost B, asshown by the arrows, as follows: wire 20, mercury-cup M, metal arm Y,mercury-cup M3 wire H72, upper steel bar, H, wire to to binding-post Band out. The heating action of the current causes the composite bar A tocurve downward at its free end afer a definite time and to carry with itthe cup G and bifurcated arm 13, thus forcing the pawl 1) forward, andwith it the whe l Il and train of gear, and hence the recordingmechanism. As shaft V is rotated to the left under this influence, itcarries with it the tilting lever It], having weight P adiustably fixedon its free end. After a time this lever and weight are carried past thecenter of oscillation, and the TOO 7 weightl then comes into play in amanner well understood in circuit-changers of this nature and causes pinit to act on the tilting circuitchanging lever B and to take its reverseposition, thereby immersing the metal points of arm Y in the mercury ofcups M and M and withdrawing arm Y from cups M and M". This change ofcircuit withdraws the current from the bar H and causes it to passthrough the lower bar, L, as follows: from B, by wire 10, to mercury-cupM arm Y, mercury-cup M, wire 10', bar L, wire 20 and out, as before.This heats bar L, and after a determinate time the operation isrepeated, each action of the composite bar giving the wheel 10 a stepforward by one of the pawls, p or 19 It will of course be understoodthat inasmuch as the heat generated in a conductor by a current ofelectricity flowing through it bears a fixed relation to the amount ofsuch current, the alternate action of the pawls controlled by the bars Hand L will be more or less rapid, dependent upon this fact.

I am aware that it is not broadly new with me to measure currents ofelectricity by their thermal effects, nor is it novel with me to measure and record currents of electricity by such agency, and I do nottherefore claim, broadly, the application of such principle, myinvention being directed to the apparatus described and claimed forutilizing or employing suc cessively the effects due to changes intemperature of two thermal conductors with circuitcontrolling devicesfor passing the circuit successivel y through said conductors andcausing a record to be made.

What I claim, and desire to secure by Letters Patent of the UnitedStates, is v 1. In a meter for measuring and recording currents ofelectricity, the combination of two conductors adapted to expand underthe influence of an electrical current, said conductors being connectedelectrically to an additional conductor carrying the currentto bemeasured, with switch mechanism and connections for throwing the currentsuccessively through said expansible conductors and recording mechanismcontrolled thereby, substantially as described.

2. A meter for measuring and recording elec trical currents, consistingof two conductors adapted to expand under the influence of an electricalcurrent, and each having one end connected to switch mechanism forthrowing said conductors into circuit successively, the other ends beingconnected to the external circuit and having mechanical connection witha recording-meter, substantially as described.

3. A meter for measuring electrical currents, consisting of a compoundthermal bar having two conducting parts, said bar being rigidly fixed atone end and having mechanical connections at its free end with arecording-meter, the conducting portions of said bar being connectedelectrically with the exteriorcircuit, and switch mechanism for throwingsaid parts successively into circuit, substantially as described.

4. In a meter for measuring electrical currents, the combination of acompound conductor having two conducting parts insulated from each otherand adapted to expandunder theinfluence of an electrical current, saidparts being each electrically connected at one end to a switch forchanging the circuit from one to the other, with a step-by-st-epapparatus mechanically connected to the free end of said compoundthermal conductor and a recorder controlled by said step-by-stepmechanism, substantially as described.

FRANK O. XVAGNER.

Witnesses:

GEO. B. VANCE, A. T. STEVENSON.

